More people than ever are using mobile stations, such as cell phones and personal digital assistants (collectively, access terminals), to connect to wireless wide area networks (WWANs), each of which (or a plurality taken together) may also be referred to as a radio access network (RAN), and by other names. Service providers typically operate RANs to provide both voice and data services using a wireless communication format (i.e., protocol).
In a typical RAN, a given access terminal communicates with one or more antennae of one or more of an entity known as a base transceiver station (BTS) via a radio-frequency (RF) air interface, thus establishing a communication path between the access terminal and the RAN. Also in a typical RAN, a given geographical area is divided into a number of smaller wireless-coverage areas such as cells and sectors, each having at least one associated BTS antenna, which are in turn coupled to an entity typically known as a base station controller (BSC), which is then coupled to at least one telecommunications switch or gateway, such as a mobile switching center (MSC) and/or a packet data serving node (PDSN), as examples.
A given switch or gateway may then be coupled with a transport network, such as the well-known PSTN (Public Switched Telephone Network) or one or more packet-switched networks (e.g., the Internet), a collection of two or more of which may for simplicity be referred to herein at times as a single packet-switched network, though this usage is for clarity of presentation, and not to imply a selection between the singular and the plural. Network devices with which an access terminal synchronizes may be disposed within the RAN itself and/or may be accessible via the PSTN, a packet-switched network, or some other network coupled to the RAN.
Moreover, cells in a given RAN are usually divided geographically into a number of sectors, each defined respectively by radiation patterns from directional-antenna components of respective BTSs, or by respective BTS antennae. These sectors (which can be visualized ideally as pie pieces) can be referred to as “physical sectors,” since they are physical areas of a cell site. Therefore, at a given time, an access terminal in a RAN may be positioned in a given physical sector, and will thus be able to access voice and data services provided by the RAN via at least the BTS serving that physical sector.
The voice and data services may be used by one or more various applications running on an access terminal, such as e-mail clients, calendars, web browsers, video-streaming clients, mapping programs, games, social-networking tools, weather programs, etc. Each of these applications may be configured to periodically contact a network device via the RAN to receive new and/or updated data pertinent to the particular application. The period in between update requests is often and herein referred to as the data-synchronization interval. Various applications may be set to use different respective data-synchronization intervals. For example, an e-mail client may be configured to have a shorter data-synchronization interval than a weather application, as e-mail inboxes tend to change more often than the weather, and users typically expect near-real-time status of their e-mail.